The specific causes of shortness of breath in women during pregnancy are not exactly the same among different individuals. The specific reasons are as follows: 1, thyroid nodules, many women may suffer from thyroid disease, due to thyroid nodules or enlarged thyroid gland, compression of the adjacent trachea, so that its ventilation function is restricted, causing symptoms of shortness of breath. 2, phytodysfunction, early pregnancy, endocrine function changes, affecting the function of the phytodysfunction and shortness of breath, is a physiological reaction in early pregnancy. 3. The symptoms of shortness of breath can be caused by eating too much at once, especially in women in late pregnancy. 4, anemia, if serious iron deficiency anemia occurs in the middle and late pregnancy, the oxygen-carrying capacity of the blood decreases, leading to a lack of oxygen in the body of pregnant women and causing symptoms of shortness of breath. 5, heart disease, heart disease caused by an excessive burden on the heart during pregnancy can also cause shortness of breath. It can cause shortness of breath, so pay attention to seek medical attention in time.